title: Citronellal, a monoterpene present in Java citronella oil, attenuates mechanical nociception response in mice.
abstract: BACKGROUND
  Citronellal is a monoterpene present in the oil of many species, including Cymbopogon winterianus Jowitt (Poaceae).
  
  
  OBJECTIVE
  The present study investigated the effect of citronellal on inflammatory nociception induced by different stimuli and examined the involvement of the NO-cGMP-ATP-sensitive K⁺ channel pathway.
  
  
  METHODS
  We used male Swiss mice (n = 6 per group) that were treated intraperitoneally with citronellal (25, 50 or 100 mg/kg) 0.5 h after the subplantar injection of 20 μl of carrageenan (CG; 300 µg/paw), tumor necrosis factor-α (TNF-α; 100 pg/paw), prostaglandin E₂ (PGE₂; 100 ng/paw) or dopamine (DA; 30 μg/paw). The mechanical nociception was evaluated at 0.5, 1, 2 and 3 h after the injection of the agents, using a digital analgesimeter (von Frey). The effects of citronellal were also evaluated in the presence of L-NAME (30 mg/kg) or glibenclamide (5 mg/kg).
  
  
  RESULTS
  At all times, citronellal in all doses inhibited the development of mechanical nociception induced by CG (p < 0.001 and p < 0.01) and TNF-α (p < 0.001, p < 0.01, and p < 0.05). The citronellal was able to increase the pain threshold in the DA test (p < 0.001, p < 0.01, and p < 0.05) and in the PGE₂ test at all times (p < 0.001 and p < 0.05). L-NAME and glibenclamide reversed the antinociceptive effects of the citronellal at higher doses in the PGE₂ test.
  
  
  CONCLUSIONS
  These data suggest that citronellal attenuated mechanical nociception, mediated in part by the NO-cGMP-ATP-sensitive K⁺ channel pathway.
authors.affiliation: Department of Physiology, Federal University of Sergipe, Aracaju-SE, Brazil.
authors.forename: Marilia Trindade
authors.initials: MT
authors.lastname: de Santana
authors.forename: Makson Gleydson Brito
authors.initials: MG
authors.lastname: de Oliveira
authors.forename: Michele Fraga
authors.initials: MF
authors.lastname: Santana
authors.forename: Damião Pergentino
authors.initials: DP
authors.lastname: De Sousa
authors.forename: Danielle Gomes
authors.initials: DG
authors.lastname: Santana
authors.forename: Enilton Aparecido
authors.initials: EA
authors.lastname: Camargo
authors.forename: Aldeídia Pereira
authors.initials: AP
authors.lastname: de Oliveira
authors.forename: Jackson Roberto Guedes da Silva
authors.initials: JR
authors.lastname: Almeida
authors.forename: Lucindo José
authors.initials: LJ
authors.lastname: Quintans-Júnior
mesh_terms: D000080462:Acyclic Monoterpenes; D000447:Aldehydes / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000627:therapeutic use*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006152:Cyclic GMP / Q000037:antagonists & inhibitors / Q000378:metabolism*; D031743:Cymbopogon / Q000737:chemistry; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D007214:Indonesia; D054086:KATP Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D051379:Mice; D039821:Monoterpenes / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000627:therapeutic use*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D059226:Nociceptive Pain / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control*; D009822:Oils, Volatile / Q000737:chemistry; D017288:Pain Threshold / Q000187:drug effects; D010938:Plant Oils / Q000737:chemistry; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000080462:Acyclic Monoterpenes; D000447:Aldehydes; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004791:Enzyme Inhibitors; D054086:KATP Channels; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D026902:Potassium Channel Blockers; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP; C108217:citronellal; C076730:citronella oil; D005905:Glyburide; D019331:NG-Nitroarginine Methyl Ester